1. Field of the Invention
The present invention relates to an orthodontic appliance, and more particularly to a means for attaching a headgear device to a tooth positioner, preformed or custom made.
2. Description of the Prior Art
In order to obtain movement of the teeth to effect an orthodontic treatment, it is necessary to allow a force to be applied to the teeth. Typically, bands on the individual teeth in conjunction with arch-wires have been used. However, this treatment requires the expenditure of a great deal of the practitioner's time and labor in addition to the disadvantages of having the apparatus firmly affixed in the patient's mouth for an extended period of time. Thus, there has been an increasing interest in the use of tooth positioner's both custom-made and preformed devices, (see my U.S. Pat. No. 3,898,736 regarding such preformed devices).
These positioning devices are adapted to be worn between the teeth of the upper and lower jaw, and are activated through the activity of masticatory, lingual, labial, and buccal muscles. Their correcting action depends to a great extent upon an accurate fit or engagement with the teeth. Prior to the preformed positioners, it was necessary to take accurate impressions of the patient's teeth and adjacent soft tissues, and to carefully fashion the appliance to fit the individual patient.
The headgear dental appliance was developed in part to avoid the fitting problems associated with these custom-made bands. These devices consisted of a mouthpiece formed of a resilient material having a curvature substantially conforming to the maxillary dental arch of a normal person. At the front, labial portion of the arch, either wires or a molded portion of the device would project from the arch, and out of the patient's mouth.
When wire was utilized, the wire would be molded into the entire arch and become an integral part thereof. Where the projections were made from the resilient material, wires would be attached to them outside of the mouth. In either case, the wires arched rearwardly outside of the mouth, projecting out and curving around both sides of the face, to the attachment with an elastic band. This band was stretched around the back of the head or neck and connected both ends of the wire. The stretching force was transmitted to the wires, together creating a rearward force which was applied to the teeth. U.S. Pat. Nos. 2,822,612; 2,880,509, and 2,983,046 may be seen in this regard.
However, dentitions of individuals vary greatly among the population. This readily recognizable fact has resulted in a limitation to the extent of treatment available when utilizing the known devices. The mouthpiece portions were not designed to fit the teeth but only match the approximate shape of the arch. Additionally, the known devices are structurally formed into a unit, and are not practically separable--either structurally or therapeutically.